Our goal is to understand the regulation of gene expression and to elucidate structure-function relationships in genomes of higher eukaryotes. In addition to our work with globin genes we are using cloned mRNA's from human leukemic cell line (HL60) as probes to study regulation of large groups of genes turned on and off during differentiation of neutrophils and granulocytes. This work is facilitated by the fact that we can induce HL60 cells to differentiate in vitro. We are also continuing our development of computer techniques for the analysis of nucleic acid secondary structure.